Phoenix Police continued to decline comment Thursday on what evidence was recovered from the scene where Sgt. Sean Drenth was found shot to death earlier this week near his parked patrol vehicle.

Investigators are treating the case as a homicide. Police have said they lack witnesses and there is little physical evidence collected from the lot where officers discovered Drenth's body, in an open industrial lot near the state Capitol.

Silent Witness is offering up to $10,000 reward for information in the case with the hope that someone will provide an anonymous tip leading to an arrest, though Phoenix police have yet to confirm Drenth was murdered.

Reward money was donated by Silent Witness, the 100 Club of Arizona and the Phoenix Police Sergeants and Lieutenants Association.

Police said he was neither writing a report nor responding to an emergency call when he parked at the lot near the Union Pacific Railroad tracks at Jefferson Street and 19th Avenue. The exact address is 1825 W. Jackson St.

- His funeral is scheduled for 10 a.m. at Christ's Church of the Valley, 7007 W. Happy Valley Road in Peoria. The interment immediately will follow the service at Phoenix Memorial Park, 200 W. Beardsley Road.